The present invention relates to circuit breaker switches and more particularly, to those that are resetable and small.
Prior art circuit breakers have numerous disadvantages. Many employ a "Taylor Blade" bimetallic actuator, such as shown in U.S. Pat. No. 2,503,008, which snaps due to increasing contact pressure and with appreciable amplitude. To prevent an inadvertent short circuit from occurring between the actuator when opening and the adjacent terminal, an insulating restraint is disposed therebetween. However, such restraint affects the calibration and stability of the switch, especially with high current overloads. Another problem is that a switch reset slide is spring actuated, but the spring and the slide do not have coinciding longitudinal axes. This, together with complex shapes or multiple parts, results in a structure that is easily jammed. Still another problem is that the prior art switches are enclosed in a multipiece housing, where the pieces are joined together during manufacture. Within the pieces are guide members with selected tolerances. The joining process results in excessively large tolerances since one piece is placed upon another, whereby tolerances accumulate. Yet another problem with the prior art is providing a low current circuit breaker. A resistance heater wire is used to augment the heat of the bimetallic actuator to obtain the desired lower ratings. However, it has been difficult to keep a constant spacing between the wire and the actuator, resulting in poor stability, i.e., varying open circuit trip currents.
It is therefore an object of the present invention to provide a switch with high stability.
It is another object to provide a switch that ensures smooth operation.
It is a further object to provide a switch that has accurate and close tolerances.
It is yet another object to provide a switch that can be safety miniaturized.
Still further objects include, economy, simplicity, ease of assembly, parts reduction, and quality assurance.